Breech closure for guns



BREECH CLOSURE FOR GUNS Filed July 13, 1939 Fi 1 l 40 7 as Wil'Lnw-n. in a 13:31

iii/ mm At t :1 mevs Patented Aug. 5, 1941 UNITED STATES PATENT OFFICE.

BREECH CLOSURE FOR GUNS William Summerbell, Watervliet, N. Y.

Application July 13, 1939; Serial No. 284,254-

(Granted under the act of March 3, 1883, as amended April 30, 1928; 3'70 0. G. 757) 6 Claims.

sure of the blow-back type in which a novel cartridge tray is retained in place through the instrumentality of a firing pin, and in which the firing pin is retained and controlled in both cocking and firing by means of a lever without the aid of springs.

A further object of the invention is to provide a removable cam plate in the gun frame below the breech block.

The specific nature of the invention as well as other objects and advantages thereof will clearly appear from a description of a preferred embodiment as shown in the accompanying drawing in which:

Fig, 1 is a view partly in plan and partly in section of a breech closure constructed in accordance with the invention.

Fig. 2 is a sectional view on the line 2-2 of Fig. 1 with part of the breech block in section.

Fig. 3 is a detail view in side elevation of the projection on the breech block prior to assembling the tray.

Fig. 4 is a detail view in plan of the tray.

Figure 5 is an end view of the device of Figure 4 as seen from the right.

Referring to the drawing by characters of reference there is shown a breech block A which is reciprocally mounted in a gun frame B and guided by means of rails 5 on the frame. The frame carries a gun barrel C which is fixed to the frame in any suitable manner. The front face of the breech block is formed with a conical shoulder 6 which is adapted to enter a flared recess 7 constituting the mouth of the bore or cartridge cham' ber 8 of the barrel and serving to guide the nose of a projectile being advanced into the barrel. A cylindrical projection 9 extending forwardly of the conical shoulder is adapted to enter the chamber 8.

The projection 9 is formed at its base with a peripheral annular groove 10 from which a pair of opposite entrance grooves H! I extend longitudinally to the extremity of the projection. A sleeve I2 constituting an element of a tray member adapted to fit over the projection 9 is provided internally with lugs l3l3 and the assembly is accomplished by moving the lugs through the entrance grooves H and then rotating the sleeve until oppositely arranged and variably sized apertures l4 and I5 in the sleeve and lugs are aligned with a stepped aperture It in the projection, in which position the lugs are disposed in the peripheral annular groove l0 between the entrance grooves H. The assembly is maintained by means of a headed pin which is inserted through the larger aperture l4 and moved past the center of the projection until its head I l is in engagement with the step of aperture I6, in which position the stem I8 extends into the smaller aperture in the sleeve.

The sleeve extends forwardly of the front face of the projection and in this extension the upper part is cut away so that there is provided a substantially semi-cylindrical tray [9 for receiving the base of a cartridge case D during the opera tion of advancing a round of ammunition from a magazine into the bore of the barrel. The lip of the tray is formed internally with a semi-circular rib or claw 20 which is adapted to enter the groove of the cartridge case forwardly of its rim for the purpose of acting as an anvil to support the cartridge against forward displacement with respect to the breech bolt when the cartridge is struck by the firing pin. The claw also serves, in the event of a misfire, as an extractor for Withdrawing the unfired round.

The breech block is provided with a longitudinally arranged passage 2I22 of varying diameters in which an annular shoulder 23 divides the enlarged rear portion from a reduced front portion. A firing pin slidably housed in the passage 2! includes an enlarged head 24 on its rear end and a reduced elongated stem 25 terminating in the usual point 26. The stem is provided with a peripheral annular groove 27 and a communicating forwardly directed groove 28 extending into the base of the point. The annular groove 21 is in line with the apertures l6 and M for the purpose of venting gases in the event of puncturing of the primer of a round.

The head 24 of the firing pin is adapted to engage the shoulder 23 to limit forward movement of the firing pin. The movement of the firing pin both in firing and in retraction is accomplished and controlled by a bell-crank lever 29 which is disposed in a recess in the lower face of the block and mounted on a pivot pin 30. One arm of the lever is formed terminally with an upright stud 3| which extends into a peripheral groove 32 in the head 24 of the firing pin while the other arm is similarly formed with a depending stud 33 which rides in a cam slot 34 when the I;

projection 9 is moving into and out of the bore of the barrel. The cam slot is arranged to rock the lever so that during forward movement of the breech block the lever will move the firing pin into firing position and during rearward movement of the breech block the lever will withdraw the firing pin to avoid damage during removal of the empty cartridge case and to prepare it for thenext firing stroke. The lever therefore serves both as a cocking instrument and as a hammer and its action is accomplished Without the use of a spring. During the major portion of the recoil and return travel of the breech block the lever is maintained in the cooking position by engagement of the stud 33 with a surface 35 of the gun frame B.

As clearly shown in Fig. 1 when the elements of the firing mechanism are assembled the firing pin serves to retain the pin Hl8 in place and the lever 29 serves to retain the firing pin. By virtue of this construction aand arrangement the assembly and disassembly of the firing mechanism may be accomplished Without the use of tools, A plug 36 may be provided to close the passage 2| and exclude dirt.

The cam slot 34 is preferably provided in a removable plate 3'! whose front face is formed with a horizontal tongue 38 receivable in a groove 39 in the gun frame B to prevent vertical displacement and Whose rear face is formed with spaced lugs 49-48 for receiving a spring-pressed plunger 4| carried by the frame and preventing horizontal displacement.

The mechanism for checking the recoil of the breech block and returning it into firing position or into battery forms no part of the present invention. Such mechanism which may be either mechanical, hydraulic or pneumatic is indicated generally by the bar 32 which is connected to the breech block by lugs 43 and extends forwardly thereof.

The upper face of the breech block is formed with a relatively deep recess 44 and with spaced grooves 4545 for accommodating a cartridge feeding magazine (not shown).

In operation the breech block functions in a manner similar to that shown in the patent previously mentioned. Initial loading of a round of ammunition into the gun barrel is accomplished by retracting the block to provide for cooking of the firing pin and to position the block for advancing a round from a magazine into the bore of the barrel. As the breech block approaches the in battery position with the projection 9 moving into the cartridge chamber 8 of the barrel the lever 29 is rotated to drive the firing pin forwardly to fire the round before the breech block reaches the rear face of the barrel. In this manner the gas pressure is first utilized to arrest the forward motion of the breech block before acting to drive it rearwardly in recoil. The empty cartridge case is blown out rather than being extracted by the claw.

I claim:

1. In a breech closure of the blow-back type, a reciprocal breech block having a projection adapted to enter a cartridge chamber of a barrel, a cartridge-engaging member on the projection, a pin operably engaging said member and projection to retain said member in place, a movable firing pin in the block retaining said retaining pin and a cooking and firing lever mounted in the block and engaging the firing pin.

2. In a breech closure of the blow-back type, a reciprocable breech block having a cylindrical projection adapted to enter a cartridge chamber of a barrel, said projection formed with a peripheral annular groove and longitudinal entrance grooves, a sleeve fitting over the projection and having internal lugs movable through the entrance grooves into the annular groove, said projection and sleeve having a through stepped aperture, a headed pin insertable in said aperture and movable past the center of the projection into final position to engage and retain the sleeve, and a firing pin in the block and retaining the headed pin in place.

3. In a breech closure of the blow-back type, a reciprocable breech block having a projection adapted to enter a cartridge chamber of a barrel, a cartridge-engaging member on the projection, said projection and member having aligned aperture holding said member in place on the projection, a retaining pin in the aperture, and a firing pin in the block retaining the retaining pin in place, said firing pin having a gas venting passage in communication with the apertures for the retaining pin.

4:. In a breech closure of the blow-back type, a reciprocable breech block having a projection adapted to enter a cartridge chamber of a barrel, a cartridge-engaging member on the projection, said projection and member having aligned apertures, a retaining pin in the apertures holding said member on the projection, and a firing pin in the block holding the retaining pin in place.

5. In a breech closure of the blow-back type, a reciprocable breech block having a projection adapted to enter a cartridge chamber of a barrel, a sleeve covering the projection and including a substantially semi-cylindrical cartridge tray, a substantially semi-circular claw on the tray, and a pin within the projection adjacent its base and engaging the sleeve to hold it in place.

6. In a gun, a frame, a breech block reciprocable in the frame, a firing mechanism in the breech block, a cam plate for the firing mechanism, a tongue and groove connection between one end of the cam plate and the frame, and a plunger carried by the frame for engaging the opposite end of the cam plate.

WILLIAM SUMMERBELL.

CERTIFICATE OF CORRECTION Patent No. 2,251,5Oh. August 5, 19).;1.

WILLIAM SWERBELL.

It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows: Page 2, sec 0nd column; lines 51, 52, and 55, for "aperture holding said member in place on the projection, a retaining pin in the aperture," read -apertures,

a retaining pin in the apertures holding said memberin place on the projeotion,-; and that the said Letters Patent should be read with this cor rection therein that the same may conform to the record of the case in the Patent Office.

Signed and sealed this 25rd day of September, A. D. 19Ln.

Henry Van Arsdale, (Seal) Acting Commissioner of Patents.

' CERTIFICATE OF CORRECTION. Patent No. 2,2515%. August 191 1.-

WILLIAM SUMMERBELL. It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows: Page 2 second column; lines 51, 52, and 55, for "aperture holding said member in place on the projection, a retaining pin in the aperture,'. read --apertures,

a retaining pin in the apertures holding said memberin place on the projection,-; andthat the said Letters Patent should be read with this correction therein that the same may conform to the record of the case in the Patent Office.

Signedan'd sealed this 25rd day of September, A. D. 19141.

Henry Van Arsdale,

(Seal) Acting Commissioner of Patents. 

